DOS Games Discussion

I need help on a game calles famer jack in harvest havoc from crono. I have the sinclair zx spectrum demo version of the game. I am not all that good at the game. The game sort of combines boulder dash,dig dug, and a some strategy. I can't pass the third level on the three level demo.
It is a fairly new game from crono who makes games for old systems like the spectrum,commodore vic-20,commodore 64,acorn,amstrad and more.